| Cotton is one of the most important economic crops in the word. It can provide renewable natural fiber source for various fields, such as textile industry and human life. With the development of society and improvement of the living standard of human, not only the quantity but also high quality of cotton fiber is increasingly required, which in turn makes the research activities focusing on improving both the fiber yield and quality. In this research, a RIL population was developed from the upland cotton cross of SGK9708, a line derived from Zhongmiansuo41 which is widely cultivated in the Yellow River Valley and 0-153, an elite cultivar of upland cotton harboring strong fiber strength gene from Asiatic cotton sources. Cotton 70 k SNP chip was used for detecting SNP markers and constructing a high density genetic map. QTLs for yield and fiber quality traits were identified using the composite interval mapping method. These works would provide an important reference for marker-assisted breeding.The absolute skewness values of all the phenotype data of yield and fiber quality traits in all the environment were less than one indicating that these data showed normal distribution which fit to the quantitative trait controled by multiple micro-effect genes. So the other phenotype data in the other 10 environments investigated by Sun Fuding and Jia Fei were.The correlation analysis showed that fiber length was significantly positively correlated to fiber uniformity and fiber strength, micronaire was significantly negatively correlated to fiber length and fiber strength, boll weight was significantly positively correlated to seed index, lint percentage was significantly negatively correlated to seed index. Fiber strength was significantly negatively correlated to ball weight and lint percentage, fiber length was significantly negatively correlated to lint percentage. It suggested that improving both the yield and fiber quality at the same time could be difficult.Totally 63058 SNP probes of the 70 K SNP chip were applied in the parents 0-153 and SGK97087 and their corresponding 196 RIL population for polymorphism screening, and 6898 polymorphic makers had been achieved. Highmap software was used to construct the genetic map with the 6898 polymorphic markers. The largest 26 groups was selected and blasted to the cotton A genome sequence and D genome sequence databases in order to assort the linkage groups to the corresponding chromosomes. Finally 5484 SNP markers were mapped. The total genetic distance was 4686.18 cM and the average marker interval was 0.97 cM. Among these linkage groups, the largest one harbors 386 markers while the smallest group harbors only 78 markers. In the A genome, the total genetic distance and the average marker interval were 2068.69 cM and 121.98 cM while in the D genome were 2657.49 cM and 233.86 cM respectively.WinQTLCart2.5 software and composite interval mapping method were used to identify QTLs for cotton yield traits and fiber quality traits with 11 environments in five years and six ecological locations. 46 QTLs for yield traits, which were stably expressed in more than two environments, were identified, including 14 QTLs for Boll weight, 14 for lint percentage and 18 for seed index. 60 QTLs for fiber quality traits, which were stably expressed in more than two environments, were identified including 14 QTLs for fiber length, 8 for fiber uniformity, 11 for micronaire, 9 for fiber elongation and 18 for fiber strength. These QTL clustered in chromosomes A1, A2, A5, A7, A9, A10, A12 and A17 in A genome, as well as in chromosomes D5, D9, D10 and D12 in D genome. These results will make a contribution to the pyramiding breeding, functional gene investigations and improving the yield and fiber quality simultaneously. |
PDF Full Text Request